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<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>

        /* 选中第一个li元素 
        li:first-child {
            color:red;
        }
*/
        /* 选中最后一个元素 
        li:last-child{
            color:blue;
        }
       

        li:nth-child(even){
              color:yellow  
        }
        li:nth-child(odd){
              color:red  
        }
        */
        li:nth-child(2n+1) {
            color:red;
        }
    </style>
</head>
<body>
    <ul>
        <li>Lorem ipsum dolor sit.</li>
        <li>Ratione ex doloremque labore!</li>
        <li>Sapiente architecto inventore itaque!</li>
        <li>Error modi quaerat quae.</li>
        <li>In blanditiis sed aperiam.</li>
        <li>Autem quod ipsum amet.</li>
        <li>Tenetur nobis eveniet non?</li>
        <li>Voluptates deleniti ipsam ipsa!</li>
        <li>Eveniet odio id possimus.</li>
        <li>Fugiat quod quos adipisci!</li>
    </ul>
</body>
</html>